1. Field of the Invention
The present invention relates generally to a sound signal generator testing apparatus, and particularly to a sound signal generator testing apparatus for preventing reflected sound signals to affect a testing result.
2. Description of Related Art
After manufactured, sound signal generators such as speakers, are tested to ensure that sound parameters meets predetermined values. During the test, the sound signal generators are placed inside of a testing apparatus. The testing apparatus is a hermetically sealed enclosure. Sound signals generated by the sound signal generators are reflected back by the inner wall of the hermetically sealed enclosure. Those reflected sound signals become noises relative to the sound signals, and affect the testing result.
Generally, acoustical absorbent is used to cover the inner wall of the hermetically sealed enclosure to suppress the reflected sound signals. In the hermetically sealed enclosure, the high frequency sound signals and the medium frequency sound signals can be easily absorbed by the acoustical absorbent in a relative small size of the hermetically sealed enclosure. However, the low frequency sound signals are difficult to absorb. In order to absorb the low frequency sound signals, the size of the hermetically sealed enclosure must be increased.
What is needed is a sound signal testing apparatus that can suppress low frequencies of reflected sound signals (echoes) of sound signals from sound signal generators, without increasing size of the sound signal testing apparatus.